Bacteriophage P22 is a type of virus that specifically infects bacteria, particularly Salmonella species. It belongs to the family of viruses known as Podoviridae and has a unique structure, featuring an icosahedral head and a short tail. P22 is often used in scientific research due to its ability to transfer genetic material between bacteria, a process known as transduction. This bacteriophage was first discovered in the 1950s and has since become a model organism for studying viral behavior and genetics. Researchers utilize P22 to explore various biological processes, including bacterial evolution and the mechanisms of viral infection. Its relatively simple structure makes it an ideal candidate for laboratory studies.